MR dacryocystography in the evaluation of patients with obstructive epiphora treated by means of interventional radiologic procedures

Non-contrast MR dacryocystography for the evaluation of epiphora and recurrent dacryocystitis: A preliminary study

INTRODUCTION

Obstruction of the lacrimal drainage represents a common ophthalmologic issue. The blockage may interest any level of the lacrimal drainage pathway, and it is important to find the site of obstruction to plan the most appropriate treatment. In this study, findings from magnetic resonance (MR) dacryocystography were compared with findings from endoscopic and surgical procedures to evaluate the accuracy of MR dacryocystography in localizing the site of nasolacrimal duct obstruction.

METHODS

We enrolled twenty-one patients with clinical suspicion of nasolacrimal duct obstruction who underwent dacryoendoscopy and surgery. MR dacryocystography was performed with a heavily T2-weighted fast spin echo sequence in the coronal planes. Before the MRI was performed, a sterile 0.9% NaCl solution was administered into both conjunctival sacs. For each examination, two independent readers (with 8 and 10 years of experience in head and neck imaging) evaluated both heavily 3D space T2-weighted and STIR sequences.

RESULTS

Stenosis/obstruction of nasolacrimal duct or lacrimal sac was diagnosed in all 21 patients who underwent MRI dacryocystography. In particular, the site of the obstruction was classified as lacrimal sac in 12 (57%) patients, nasolacrimal duct in 6 (29%) patients, and canaliculi in 3 (14%) patients by both readers. By comparison with the evidence resulting from the endoscopy, there were differences between MRI dacryocystography and dacryoendoscopy in the evaluation of the obstruction's site in three patients, with an overall accuracy of 85.7%.

CONCLUSION

MR dacryocystography allows a non-invasive evaluation of the lacrimal drainage pathway, valid for the planning of the most appropriate treatment.

Evaluation of epiphora by topical contrast-enhanced CT and MR dacryocystography: which one to choose?

BACKGROUND

Our study aims to compare non-invasive imaging such as topical computed tomography dacryocystography (CTD) and topical magnetic resonance dacryocystography (MRD) in patients with epiphora.

PURPOSE

To evaluate the practicability of topical contrast media during helical CTD and topical saline during MRD to reveal obstruction in the nasolacrimal drainage system (NLDS).

MATERIAL AND METHODS

Twenty participants with nasolacrimal duct obstruction were observed for two years. Ten participants underwent CTD and the other 10 participants underwent MRD. Images were analyzed by two radiologists. Participants were also asked about the level of discomfort of the contrast material versus the saline solution.

RESULTS

The NLDS was seen on both CTD and MRD. Very good agreement between the two observers (κ value > 0.81) was seen according to the κ statistics. CTD multiplanar and 3D images allowed for precise diagnosis of the point of obstruction whereas, the MRD did not require any contrast material and showed the point of obstruction. Saline was more comfortable for the patients than topical contrast (P < 0.05).

CONCLUSION

Topical CTD and MRD are non-invasive techniques that can visualize the degree and level of obstruction in the NLDS than conventional invasive cannulation dacryocystography. CTD is useful in visualizing the point of obstruction and smaller drainage structures. However, it is a source of ionizing radiation to the lens. The benefit of MRD is that it requires no contrast or radiation; however, it is poor in depicting the bone anatomy and smaller drainage structures. Finally, saline was better tolerated by patients than topical contrast.

[Modern methods in diagnostics of lacrimal system vertical part obliteration]

A review of the literature is devoted to the description of modern diagnostic methods that are directed at detecting lacrimal pathway obstruction. The presented analysis is based on the study of data from Russian and foreign literary sources on both routine and high-tech lacrimal system examination methods, as well as on authors' experience in studying the diagnostic efficiency of imaging methods such as lacrimal scintigraphy, computed tomography with lacrimal pathway contrasting, and also single photon emission computed tomography. The article gives information about the advantages and disadvantages of the presented methods, highlights the questions of the prospects of their usage in practical dacryology.

Recurrent epiphora after dacryocystorhinostomy surgery: Structural abnormalities identified with dacryocystography and long term outcomes of revision surgery : Success rates of further surgery following failed dacryocystorhinostomy surgery

Background

To investigate the aetiopathology of recurrent epiphora or stickiness after dacryocystorhinostomy (DCR) surgery, identifiable on dacryocystography (DCG), and to assess the success rates of secondary corrective surgeries.

Methods

Consecutive post-DCR DCG images from patients with recurrent symptoms were reviewed between 2012 and 2015.

Results

One hundred fifty-nine eyes of 137 patients were evaluated. Fifty-eight DCGs showed normal postoperative findings, 4 an upper/lower canalicular block, 13 a common canalicular block, 31 a completely closed anastomosis, 50 a narrow anastomosis, and 3 an anastomosis draining into a nasal sinus.

The most successful corrective procedures for each failure category were: Lester Jones Tube (LJT) for a normal post-operative DCG (17/18 success), Sisler trephination with tubes for upper/lower canalicular block (1/2 success), redo-DCR with tube for common canalicular blockage (5/6 success), redo-DCR +/− tube for completely closed anastomosis (12/16 success), LJT followed by redo-DCR +/− tube for narrow surgical anastomosis (1/1 and 17/27 success respectively), and redo-external-DCR with tube for anastomosis into a nasal sinus (1/1 success). Redo-DCR was ineffective in patients who had good post-DCR anatomical patency (22% success).

Conclusion

This is the first study to report success rates of redo-DCR surgery according to anatomical findings confirmed by DCG. The outcome flow diagram help clinicians recommend procedures that are most likely to be successful for their patient’s specific anatomical abnormality. It also provides a visual tool for the shared decision-making process. Notably, symptomatic patients with a normal DCG post DCR are unlikely to benefit from redo-DCR, with a LJT being the recommended next step.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12886-021-01869-8.

Tear transit time evaluation using real-time technique for dynamic MR dacryocystography

Purpose: To explore the utility of a novel real-time dynamic magnetic resonance dacryocystography (MRDCG) technique to assess the transit times through the lacrimal drainage system (LDS). Methods: Twenty-six patent LDS of 13 normal and asymptomatic individuals underwent MRDCG using a dynamic recalled three-dimensional spoiled gradient sequence (3DSPGR) on 1.5-Tesla magnetic resonance (1.5T MR) scanner while pre-determined diluted gadolinium drops were instilled into the eyes simultaneously. MR images of 0.8 mm thickness were captured every 9.4 s for 10 min. Evaluated parameters include the time taken for contrast to first appear in lacrimal sac, nasolacrimal duct (NLD), and inferior meatus (IM). Results: Dynamic MRDCG demonstrated contrast outflow in all cases with good structural delineation. The mean transit time for contrast to appear in lacrimal sac was 15.2 s (9.4-66 s; SD, 11.9), 50.4 s for nasolacrimal duct (18.9-151; SD, 32), and 150.5 s for inferior meatus (37.8-490; SD, 135). Contrast appeared in the IM in less than 2 min in 62% (16/26) systems, and only 19% (5/26) required more than 5 min. The maximum time taken for the contrast to reach IM was 6.2 min and all the LDS eventually showed the contrast into the nasal cavity. No statistically significant differences were noted in the transit times between the right and left sides. Conclusion: Dynamic MR-DCG using real-time 3DSPGR sequence reliably demonstrates the structural and physiological assessment of LDS and could be further explored to study the physiology and pathologies of the LDS.

Nasolacrimal stent with shape memory as an advanced alternative to silicone products

Epiphora is the overflow of tears typically caused by obstruction or occlusion of the nasolacrimal duct. More attention is required to address this global health issue owing to the increase in air pollution. Implantation of a silicone stent is the preferred treatment for epiphora; however, introducing a silicone stent into a narrow duct with complex geometry is challenging as it requires guidance by a sharp metal needle. Additionally, silicone can cause adverse reactions such as biofilm formation and tear flow resistance due to its extreme hydrophobicity. To overcome these problems, in this study we developed a new type of biocompatible shape memory polymer (SMP) stent with elasticity capacity for self-expansion. First, SMPs in the form of x%poly(ε-caprolactone)-co-y%poly(glycidyl methacrylate) (x%PCL-y%PGMA) were synthesized via ring opening polymerization by varying the molar ratio of PCL (x%) and PGMA (y%). Second, the shape memory and mechanical properties were tuned by controlling the crosslinking degree and concentration of x%PCL-y%PGMA solution to produce a test type of SMP stent. Lastly, this 94%PCL-06%PGMA stent exhibited more standout critical functions in a series of in vitro and in vivo experiments such as a cell growth-supporting level of biocompatibility with nasal epithelial cells without significant inflammatory responses, better resistance to biofilm formation, and more efficient capacity to drain tear than the silicone control. Overall, 94%PCL-06%PGMA can be suggested as a superior alternative to the currently used materials for nasolacrimal stents. STATEMENT OF SIGNIFICANCE: Silicone intubation (stenting) has been widely used to treat nasolacrimal duct obstruction, however, it can cause adverse clinical effects such as bacterial infection; presents procedural challenges because of the curved nasolacrimal duct structure; and shows poor drainage efficiency stemming from the highly hydrophobic nature of silicone. In this work, we describe an innovative shape memory polymer (SMP) as a superior alternative to conventional silicone-based materials for nasolacrimal duct intubation. We demonstrate the clear advantages of the SMP over conventional silicone, including a much higher drainage capacity and superior resistance to bacterial infection.

A Comprehensive Review of Cross-Sectional Imaging of the Nasolacrimal Drainage Apparatus: What Radiologists Need to Know

OBJECTIVE. The purpose of this study is to provide a comprehensive review of the radiographic anatomy and cross-sectional imaging findings of the full gamut of nasolacrimal drainage apparatus diseases, highlighting imaging findings from the different nasolacrimal drainage apparatus surgeries, posttreatment complications, and potential imaging pitfalls. CONCLUSION. Radiologists play a critical role in guiding the management of nasolacrimal drainage apparatus diseases and should be familiar with the anatomy and characteristic imaging findings of commonly encountered nasolacrimal drainage apparatus abnormalities and surgeries.

Dacryocystography: From theory to current practice

PURPOSE

To provide a review and an update on dacryocystography (DCG) and its relevance in the current era.

METHODS

The authors performed a PubMed search of all articles published in English on DCG, digital subtraction-DCG (DS-DCG), computed tomographic DCG (CT-DCG) and magnetic resonance-DCG (MR-DCG). Data analyzed include the indications, techniques, interpretations, complication and limitations.

RESULTS

Dacryocystography has been used for illustrating the morphological and functional aspects of the lacrimal drainage system (LDS). Subtraction DCG provides the precise location of the alterations and acceptably delineates stenosis or an obstruction. Transit time for contrast into the nose varies widely across the studies. Low osmolality iodinated contrast media are tolerated well for DS-DCG and CT-DCG. However, normal saline either mixed with lidocaine or alone provided similar image quality as obtained with gadolinium for MR-DCG. CT-DCG provides useful information in complex orbitofacial trauma and lacrimal tumors. MR-DCG allows better 3D visualization of the LDS and dynamic functional evaluation. Sensitivity of CT-DCG and MR-DCG are mostly similar in identifying an LDS obstruction.

CONCLUSION

Various forms of DCGs can provide additional information to evaluate patients with maxillo-facial trauma, functional epiphora, suspected lacrimal sac diverticula, partial nasolacrimal duct obstruction, and lacrimal drainage tumors. Canaliculi and the membranous part of the nasolacrimal duct are not yet visualized in detail and further focused studies with advanced techniques are required.

Value of ultrasound biomicroscopy in assessment of small masses at medial canthal region

PURPOSE

Conventional imaging techniques are not sensitive enough to reveal detailed structures of lacrimal drainage system (LDS) and its surrounding tissue (ST). Our study aimed to explore utility of ultrasound biomicroscopy (UBM) in assessment of small masses at the medial canthal region and compare performance of UBM with conventional imaging techniques.

METHODS

We prospectively recruited cases with small mass (long axis < 1 cm) at the medial canthal region (upper LDS-located area) from June 2017 to October 2018. UBM ± color Doppler flow imaging (CDFI) and conventional imaging techniques (computed tomography, magnetic resonance imaging, and dacryocystography) were conducted by four independent practitioners. Results were analyzed against gold standards with Cohen's kappa test in three aspects including LDS patency, mass location, and presumptive diagnosis. Corresponding gold standards were syringe and dacryocystography, intraoperative findings, and pathological/empirical diagnosis.

RESULTS

Seventy-two cases were recruited, including 20 cases of LDS lesions and 52 cases of ST lesions. Female (odds ratio 7.14) and age ≥ 37 (odds ratio 9.80) were risk factors for LDS lesion, and age range of 15-25 (odds ratio 9.17) was a risk factor for inflammatory ST lesion. In terms of LDS patency, UBM results were reliable for the detection of pre-saccal obstruction (kappa = 0.920), but were not reliable for intra-saccal and post-saccal obstruction (kappa = 0.106). In terms of mass location, the UBM (kappa = 0.766) performed better than conventional techniques (except for dacryocystography) to sort out ST lesions, with sensitivity of 93.8% and specificity of 83.3%. In terms of diagnosis, the UBM (kappa = 0.882) outweighed conventional techniques (except for magnetic resonance imaging) to distinguish cysts from nodules, with sensitivity of 93.8% and specificity of 94.4%. Notably, the UBM + CDFI achieved better performance than the UBM when screen out inflammatory lesions (kappa = 0.926 vs kappa = 0.689) and LDS-adjacent lesions (kappa = 0.815 vs kappa = 0.673), resulting in sensitivity of 91.7% and specificity of 100% for both testing items. If deep lesions (at the lacrimal sac-harbored area) were excluded, UBM reliability to detect inflammatory lesions (kappa = 0.915) and LDS-adjacent lesions (kappa = 0.770) improved, achieving sensitivity of 90.0% and 88.9%, and specificity of 100.0% and 92.7%, respectively.

CONCLUSIONS

The UBM is a valuable tool to assess superficial masses at the medial canthal region regarding pre-saccal obstruction, mass location, and presumptive diagnosis.

TRIAL REGISTRATION

This work was registered on Chinese Clinical Trial Registry website with registration number ChiCTR1800018956 .

[Comparison of 3T dacryo-MRI by instillation with dacryo-CT scan for evaluation of epiphora]

OBJECTIVES

Epiphora is frequently related to stenosis of the lacrimal drainage pathways. In the evaluation of stenosis, dacryo-CT scan remains the gold standard, despite the need for radiation and catheterization of the lacrimal passages. Evaluation by high field 3T MRI compared to the gold standard in the morphological study of the lacrimal passages and quantification of the stenosis is attractive considering the lack of radiation and non-invasive nature of the technique.

METHODS

Twenty-four patients were included, including 9 with bilateral epiphora, representing 33 pathological drainage systems out of 48. Twenty-three drainage systems underwent subsequent surgery (18 patients, 5 patients bilaterally).

RESULTS

The average diameter on CT scan images of the superior canaliculus was 0.70 mm (± 0.46), of the inferior canaliculus 0.69 (±0.42), the common canaliculus 0.68 (± 0.58), the lacrimal sac 4.32 (± 2.10), and the nasolacrimal duct 1.15 mm (±1.42). 3T dacryo-MRI overestimated the diameters by 0.35 to 1mm (up to 20 % of the lacrimal sac size), and the concordance between dacryo-CT scan and 3T dacryo-MRI was of average value (kappa 0.5, P<0.05) concerning the diagnosis of stenosis. Furthermore, dacryo-CT scan demonstrated higher sensitivity (72.7 %) than 3T dacryo-MRI (42.4 %).

CONCLUSIONS

The two techniques are not equivalent in the diagnosis of stenosis. An optimization of protocols and an evaluation on a larger cohort remain necessary before dacryo-CT scan can be replaced by dacryo-MRI in routine practice.

Update on imaging techniques in oculoplastics

Imaging is a beneficial aid to the oculoplastic surgeon especially in orbital and lacrimal disorders when the pathology is not visible from outside. It is a powerful tool that may be benefited in not only diagnosis but also management and follow-up. The most common imaging modalities required are CT and MRI, with CT being more frequently ordered by oculoplastic surgeons. Improvements in technology enabled the acquisition times to shorten incredibly. Radiologists can now obtain images with superb resolution, and isolate the site and tissue of interest from other structures with special techniques. Better contrast agents and 3D imaging capabilities make complicated cases easier to identify. Color Doppler imaging is becoming more popular both for research and clinical purposes. Magnetic resonance angiography (MRA) added so much to the vascular system imaging recently. Although angiography is still the gold standard, new software and techniques rendered MRA as valuable as angiography in most circumstances. Stereotactic navigation, although in use for a long time, recently became the focus of interest for the oculoplastic surgeon especially in orbital decompressions. Improvements in radiology and nuclear medicine techniques of lacrimal drainage system imaging provided more detailed analysis of the system.

Update on imaging of the lacrimal drainage system

Epiphora is a common problem seen by the ophthalmologist. There are numerous etiologies of a watering eye, and the underlying diagnosis is not always clear. A variety of in-office examination techniques and procedures exist to aid with diagnosis and determination of appropriate therapy, but sometimes the diagnosis remains elusive, or an instituted therapy fails. Lacrimal imaging, particularly in these cases, can be helpful in assessing the function and anatomy of the lacrimal drainage system. This review serves to examine the literature of the last 10 years concerning imaging of the lacrimal drainage system.